1. Field of the Invention
This invention relates generally to the field of high gain antenna structures suitable for vertical stacking. More particularly, this invention relates to a vertically polarized antenna structure exhibiting omni-directional coverage in the horizontal plane and high gain at the horizon. In ground based communication systems, such as paging systems, it is desirable for the paging transmitter antenna to exhibit vertical polarization with omni-directional coverage in the horizontal plane and high gain at the horizon in order to achieve maximum enhancement of range in the communication systems.
2. Background of the Invention
In the prior art, various colinear series fed arrays have been utilized in such ground based communication systems. Unfortunately, such antenna configurations must be series fed and when many sections are stacked to obtain high gain, a notable loss in bandwidth is experienced.
The present invention is directed towards an antenna section which may be readily stacked to obtain high gain without sacrifice of bandwidth. In this antenna structure, the bandwidth is determined by each individual antenna section. Each section is parallel fed and all interconnecting cables between sections may be hidden within a central conductive cylinder thereby eliminating the problem of antenna pattern disruption by interference and scattering from the transmission lines that feed the individual antenna sections.